Isaiah 22 describes Eliakim in detail. The following would be true of Him:
-He apparently was replacing another, Shebna of verses 15-19.
-The government of (the Messiah or Shebna?) would be committed to Him.
-He would be clothed with the robe of (the Messiah or Shebna?).
-He would be strengthened with the belt of (the Messiah or Shebna?).
-He would be a Father to the inhabitants of Jerusalem and the house of Judah.
-He would be given the Key of David.
-He would shut and none open, and open and none shut.
-He would be fastened as a nail in a sure place.
-He would be for a glorious throne to His Father’s house.
-All the glory of His Father’s house would be hung upon Him.
-The nail fastened in the sure place (the Messiah or Shebna?) would be removed, cut down, and fall, and the burden on it would be cut off.
Isaiah 22:20 And it shall come to pass in that day, that I will call my servant Eliakim the son of Hilkiah:
21 And I will clothe him with thy robe, and strengthen him with thy girdle, and I will commit thy government into his hand: and he shall be a father to the inhabitants of Jerusalem, and to the house of Judah.
22 And the key of the house of David will I lay upon his shoulder; so he shall open, and none shall shut; and he shall shut, and none shall open.
23 And I will fasten him as a nail in a sure place; and he shall be for a glorious throne to his father’s house.
24 And they shall hang upon him all the glory of his father’s house, the offspring and the issue, all vessels of small quantity, from the vessels of cups, even to all the vessels of flagons.
25 In that day, saith the LORD of hosts, shall the nail that is fastened in the sure place be removed, and be cut down, and fall; and the burden that was upon it shall be cut off: for the LORD hath spoken it.
Now… who is Eliakim?
I believe it is clearly the Holy Spirit, since He is the only One said to have the “Key of David.” It also says he is the one that “openeth, and no man shutteth; and shutteth, and no man openeth”:
Revelation 3:6 He that hath an ear, let him hear what the Spirit saith unto the churches.
7 And to the angel of the church in Philadelphia write; These things saith he that is holy, he that is true, he that hath the key of David, he that openeth, and no man shutteth; and shutteth, and no man openeth;
Furthermore, it was to the Holy Spirit that were committed by Jesus the government, the authority over the world to reprove and exact justice, and the guidance into all truth:
John 16:7 Nevertheless I tell you the truth; It is expedient for you that I go away: for if I go not away, the Comforter will not come unto you; but if I depart, I will send him unto you.
8 And when he is come, he will reprove the world of sin, and of righteousness, and of judgment:
9 Of sin, because they believe not on me;
10 Of righteousness, because I go to my Father, and ye see me no more;
11 Of judgment, because the prince of this world is judged.
12 I have yet many things to say unto you, but ye cannot bear them now.
13 Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come.
14 He shall glorify me: for he shall receive of mine, and shall shew it unto you.
15 All things that the Father hath are mine: therefore said I, that he shall take of mine, and shall shew it unto you.